1-23.3. GENERATING SYSTEM OPERATION (400 AMPERE DUAL VOLTAGE ALTERNATOR)
The 400-ampere dual voltage generating system maintains battery charge and provides electrical power to
operate vehicle circuits. Major components of the generating system are:
ALTERNATOR (400 AMPERE) Is rated at 28 volts at 400 amperes and 14 volts at 50 amperes
with external regulator. The alternator assists and recharges the vehicle batteries during operation.
BATTERY GAUGE Indicates electrical system voltage. It is connected to the electrical system
through circuit 567.
PROTECTIVE CONTROL BOX / DISTRIBUTION BOX* Protects the vehicle electric system in
the event battery polarity is reversed. Provides load dump, glow plug operation, and interfacing of
engine body harnesses.
CIRCUIT 2 Sends AC signal, indicating alternator shaft rpm, to frequency switch in protective
control box to prevent operation of starter solenoid when engine is running.
BATTERIES Two 12-volt batteries are connected in a series to provide 24 volts to start vehicle and
assist alternator during operation.
POSITIVE CABLE 6 Provides 28-volt alternator output to maintain charge across two batteries.
CIRCUIT 3 Connects to negative stud on alternator with engine ground strap to provide a ground
circuit to alternator.
POSITIVE CABLE 68A Provides 16-volt alternator output to maintain charge across the lower
CIRCUIT 568 Senses vehicle voltage, and activates the field current in the alternator circuit to
* Distribution box provides same function as protective control box except distribution box does not
protect against reversal of battery polarity.